Antihistamines

WHAT YOU NEED TO KNOW?

(Antihistamines)

👉Actions

Competitively block the H1-receptor sites and impede histamine-mediated responses. Second- generation antihistamines cause less drowsiness.

👉Uses

• Prevent and treat seasonal allergies; decrease itching (pruritus)

• Are adjuncts used with epinephrine for severe allergic reactions (anaphylaxis) 

• Prevent and treat motion sickness and insomnia

🚨Precautions(MAG-INGAT)

• Asthma—acute or chronic; chronic obstructive pulmonary disease (COPD) 

• Pregnancy and lactation; hypertension

• Conditions resulting in urinary retention and obstruction

👉Implications

1. Do not to take antihistamines with alcohol.

2. It causes drowsiness

3. Do not administer antihistamines within 4 days of skin testing.

4. To be taken take with food if gastrointestinal (GI) upset occurs.

5. Exercise extreme caution when driving or performing other hazardous

activities.

6. Dry mouth can be reduced by sucking on hard candy or taking frequent sips of water.

7. Avoid certain fruit juices in the interval between 4 hours before dosing and

1 to 2 hours after dosing if taking Allegra.